Circuit breaker



Sept. 18, 1945. o. 8. JENNINGS G IRCUIT BREAKER Original Filed Feb. 23, 1934 WITNESSES:

Patented Sept. 18, 1945 cmcurr BREAKER Oliver S. Jennings, Pittsburgh, Pa., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application February 23, 1934, Serial No. 712,577

' Renewed July 7, 1938 86 Claims.

My invention relates to circuit interrupters and particularly to quick-acting thermostatic devices suitable for use in controlling lighting and distribution feeder circuits.

One object of my invention is to provide an improved, quick-acting thermostat that shall be simpler and less expensive to manufacture, and that shall be more accurate and more reliable in its operation than the previously known devices of this general type.

Another object of my invention is to provide an improved snap-acting circuit interrupter that shall automatically move to the open circuit position upon the occurrence of predetermined current conditions in ithe controlled circuit, independently of the position of the operating handle.

Another object of my invention is to provide an improved multiple-link, over-center spring mechanism for use ina snap-acting circuit interrupter or other device, one of the links of my improved mechanism to be of thermally responsive material for effecting the operation thereof automatically upon the occurrence of predetermined conditions.

A further object of my invention is to provide an improved switch actuating member for use in electrical apparatus, my improved switch actuating member to be of thermally responsive material in order to obviate the necessity for the provision of a separate trip device.

A further object of my invention is to provide an improved circuit interrupter switch actuating member which shall utilize the magnetic reactions caused by the current iiow therein-to assist in opening the interrupter.

A still further object of my invention i to provide an improved multiple-link snap switch of the type wherein one link is of thermally responsive material movable to cause automatic opening of the circuit upon the occurrence of predetermined circuit conditions with a simple and ac curate adjusting means for controlling the thermally responsive link.

Since the principal field for immediate application of my invention is in connection with circuit breakers for low and moderate power circuits, I shall hereinafter describe an embodiment of my invention as applied to such devices, without, however, in any way intending to restrict the scope of my invention, except as indicated in the appended claims. y

In this embodiment of my invention, I provide a looped, current carrying switch actuating member of bimetallic material that is pivotally mounted adjacent the closed end of the loop and that is provided with contact means afilxed to one of its ends. In addition, I provide a manually operable, multiple-link, over-center mechanism for engaging and actuating the switch actuating member. This mechanism includes a portion of the switch actuating member as one of the links thereof, is trip free of the handle, and is quick make and quick break. The objects of my invention are accomplished, as will be explained in detail later, by reducing the number of the structural elements to a minimum through the utilization of the same element for a plurality of functions, by carefully proportioning and positioning the several parts and their support points, and by combining structural features into new and novel combinations.

Referring to the drawing,

Figure 1 is a side elevational view of a circuit breaker, in the open circuit position, embodying the principal elements of my invention,

Fig. 2 is a side elevational view of the circuit breaker shown in Fig. 1 in the closed circuit position,

Fig. 3 is a side elevational view partly in section showing the circuit breaker illustrated in Figs; 1 and 2, in the first stages of the tripping operation,

Fig. 4 is a sectional view taken on the line IV-IV of Fig. 3.

Fig. 5 is an exploded perspective view showing the structural details of the circuit breaker shown in Figs. 1 to 4 inclusive.

Fig. 6 is an enlarged fragmentary sectional view showing details of the support means for the switch actuating member and the operating handle, and

Fig. 'I is a diagrammatic view showing the relative position of the pivot points and the line of action of the over-center operating spring for the various possible operating conditions.

As shown in Figs. 1 to 4, inclusive, the base I of the circuit breaker is of molded insulating material and has mounted thereon two terminal con tacts 3 and 5, two stationary contact members i and 9, the main support member ii for the moving parts of the operatin mechanism, and the adjusting means l3 for controlling the operation of the thermally responsive and the magnetically responsive tripping means. Each of the two moving contacts I5 is supported on one end of a looped switch actuating member I! which is of bimetallic material. These two switch actuating members I l are mechanically and electrically connected together at the end opposite the contacts by means of a metallic strip is which is riveted thereto. A conical shaped pivot pin 2| is aiilxed adjacent the closed end of each of the looped switch actuating members H in order to provide a pivot point on which the switch actuating mem bers can rotate when moving from one circuit position to the other. The circuitbreaker shown in the drawing is of the single pole, double break type, the two switch actuating members H and their associated contacts I5 bein moved during each circuit interrupting operation to provide a pair of serially connected breaks.

The stationary contacts I and 9 and the associated terminals 3 and 5 are held in place, as is shown particularly in Fig. 4, by means of a contact supporting member 23 of insulating material, which is also used as an arc extinguishing device. This member 23 is fastened to the base of the circuit breaker by means of a screw 25 which extends through a suitable opening and engages a threaded hole 25 in the base of the U- shaped contact stop 21. Suitable cutout portions in the member 23 restrain and position the contacts and the terminals. The contact supporting member 23 is further provided with a pair of cylindrical passages 29 in order to permit the movable contact members |5 to engage the cooperating stationary contact members 1 and 9.

The bifurcated operating handle 3| is provided with a grip member 330i insulating material fastened thereto by a screw 34 (Fig. 3). A pivot pin 35 extends outwardly from the lower portion of each of the two opposed sides of the operating handle 3|; each of these pins 35 is adapted to engage, and be pivotally supported in, the opening 31 in one of the bracket members 39. As shown particularly in Fig. 5, the central portion of the support member H is cut away to form a rectangular notch 40 wherein the operating handle moves. member, which defines the base of the notch 40, is adapted to be engaged by the end 4| of each of the side portions of the operating handle in order to limit the motion of the operating handle in a counter-clockwise direction about its pivot point.

Each of the U-shaped bracket members 39 is provided, as is shown particularly in Fig. 5 with a triangular notch 45, the apex of which is substantially in line with the center of the support openings 31 for the operating handle pivot pins 35. These notches are engaged by knife edge portions 48 integral with the operating member 41 and serve as fulcrums therefor. The operating member 41 is provided with an upstanding portion 49 for engaging the operating handle 3|, a pair of downwardly extending projections 5| being provided for cooperating with the end 53 of the upstanding portion 49 so as to provide a lost motion connection between the operating handle 3| and the operating member 41. The interconnected switch actuating members l1 and the operating member 41 are held in an operative position against their pivot points by means of an over-center operating spring 55.

Movement of the switch actuating members H in a clockwise direction about their pivot points (the pins 2|) is defined by the contact stop 21. Movement of the operating member 41 in a counter-clockwise direction about its pivot point (the aligned notches 45) is defined by the engagement of the end 53 of the upstanding portion 49 with one of the downwardly extending projections 5| formin a part of the operating handle 3|, the operating handle itself being limited by the engagement of the portions 4| with the central por- The central portion 43 of the support tion 43 of the support member ll. Movement of the operating member 41 in a clockwise direction is limited by the circuit breaker adjusting means II which includes a threaded stud 51. Suitable threaded supports 55 are molded into central support member II in order to permit that memher to be fastened to the base by means oi the screw 5|. A similar support 55 is molded into the base for engaging the'adiusting stud 51, this stud being locked in any desired position by means of a locking nut 55.

As is shown particularly in Fig. 6, each of the pivot pins 2| which provide a fulcrum for the interconnected switch actuating members l1 engages a suitable conical recess 51 within a threaded insert 55. These threaded inserts 53, in turn, engage suitable threaded openings in the central support member Each of the bracket members 39 is fastened to the support member H by means of a screw 1| which engages a threaded opening in the central portion thereof.

The operation of my invention may best be described in conjunction with Figs. 1 to 3 and Fig. '1. The circuit breaker is shown in Fig. 1 in the open circuit position The over-center spring 55 has moved to a position above the pivot points of the switch actuating members i1 and the operating member 41 thereby biasing each of those members toward the open circuit position. This arrangement is illustrated diagrammatically in Pig. '1 wherein 13 represents the pivot point of the switch actuating members H, the point 15 represents the pivot point of the operating member 41, and the line 11 represents the line of action of the over-center spring 55. To clos the circuit. the operating handle 3| and with it the operating member 41 is moved in a clockwise direction about its pivot point (the pins 55); the first result is to cause the line of action of the spring 55 to coincide with the pivot point of the switch actuating member. This position is shown in Fig. '1 by the line 19. Further clockwise movement of the operating member 41 will bring the line of action to the closed circuit side of the Pivot Poin of the switch actuating members I1 thereby causing the over-center spring 55 to exert a component biasing the switch actuating members l1 toward the closed circuit position. Any further movement of the switch actuating members l1 toward the closed circuit position results in a progressive increase in this component, therefore, as soon as movement begins, it will proceed with progressive acceleration until the switch actuatting members |1 have moved the movable contacts i5 into engagement with the stationary contacts 1 and 9.

As the switch actuating members |1 move toward the closed circuit position, the line of action of the spring 55 is carried across the pivot point of the operating member 41, thereby causing the operating member to automatically move to the closed circuit position, independently of further movement of the operating handle. This mode of operation is made possible by the lost motion connection between the operating handle 2| and the operating member 41 which results from the space between the two projections 5|, and is of considerable value in securing positive and reliable operation of the circuit breaker.

When the circuit breaker is in the fully closed position, the line of' action of the over-center spring 55 is on the closed circuit side of the pivot points of both the switch actuating members I1 and the operating member 41 (this position being illustrated by the line 5| in Fig. 7) and biases both the operating member and the switch actuating member to the closed circuit position. It is important to note that the relative movement between the line of action of the spring 55 and the pivot point or the switch actuating members l1 and the operating member 41, during the circuit closing operation, takes place in such a manner that the line of action first crosses the pivot point of the switch actuating member and then crosses the pivot point of the operating member. This sequence is very desirable in securing a quick closing or the circuit and adds much to the reliability oi operation of the device.

The circuit interrupter illustrated in the draw- 8 is trip free of the operating handle in the sense that it will open the circuit with a snap action either after a time delay in response to a predetermined overload condition or substantially instantaneously upon the occurrence of a predetermined overload or short circuit condition, irrespective of the position of the operating handle. This desirable characteristic is made possible by the looped feature oi the switch actuating member itself and by the fact that the switch actuating members are made of thermally responsive material.

Upon the occurrence of an overload, the switch actuating members I! heat due to the fact that they are both carrying the full line current and in expanding tend to move away from each other. The initial stage of this action is shown in Fig. 3, and the relative positions of the center points and the line of action of the over-center spring is illustrated by the line 83 of Fig. 7. At this point, the line of action of the spring 55 coincides with the axis of the operating member 4! and, therefore, does not bias that member in either direction. However, due to the displacement of the centers of the operating member 41 and the switch actuating member H, the over-center spring 55 at this instant of zero bias on the operating member 51 does bias the contacts toward each other a with a component of force directly proportional to the distance separating the line of action of the spring 55 and the pivot point of the switch actuating members. Any additional movement of the end of the switch actuating member to which the spring 55 is aihxed will bring the line of action 01' the over-center spring to the open circuit side of the pivot of the switch operating member 41, thu creating a component of force tending to move that member toward the open circuit position. If the handle 3| is free, a very small component of force will cause movement of the operating member 41 toward the open circuit position, and since the biasing action of the overcenter spring 55 progressively increases with movement of the operating member 41 toward the open circuit position, that movement will take place at an increasingly rapid rate. The immediate result is to move the line of action of the operating spring 55 acros the pivot point oi! the switch actuating members l1, this operation being carried on at high speed, and as soon as the line of action of the over-center spring crosses the pivot point of the switch actuating members II, that member begins to move toward the open circuit position. The entire operation takes place in a very short space of time, and thus secures a rapid interruption of the controlled circuit. The bimetallic switch actuating members I! remain in the expanded condition for some time due to the necessity of cooling those members before they can return to the normal position, and while they are in the expanded position it is impossible to close the circuit breaker by movement of the operating handle. This is due to the fact that, as shown in Fig. 7, the line 85 connecting the full on position of the operating member 41 and the expanded bimetallic switch actuating member I] has not crossed the pivot 13 of the actuating member I'I.

If the operating handle is held in the full on position during the occurrence of an overload condition, a somewhat greater expansion of the bimetallic switch actuating members I! is necessary in order to cause the breaker to open the circuit, it being necessary in this case to move the end of the switch actuating members I! which engages the over-center spring 55 a suflicient distance to bring the line of action of the spring over the pivot point of the switch actuating members themselves. In a commercial structure, the actual time delay over the operation secured when the handle is not held is very small. As soon as the line of action of the over-center spring 55 has been moved to the open circuit side of the switch actuating mern bers I1, those members are caused to move to the open circuit position regardless of the position of the operating handle 3|, further the opening operation takes place with a snap action, since any movement of the switch actuating members causes the component of force producing that movement to increase progressively therewith. The open circuit position of the breaker is that illustrated diagrammatically by the line 85 in Fig. 7, and it is thus evident that the circuit breaker is trip free of the handle under all possible operating conditions.

Upon release of the handle after having been held in the on position during an overload, the biasing spring automatically returns the operating member 41 to the oil? position since the line of action of the spring has been moved to the other side of the pivot 15. After the bimetal has cooled the switch is again in the normal oiT position represented by line 11 in Fig. 7 and the switch maybe reclosed by merely moving the handle to the on position without any manual resetting operation being required.

Upon the occurrence of a very heavy overload or short circuit condition, the current flow in the looped switch actuating members I! reaches a suilicient magnitude to cause an actual mechanical separation of the opposed side portions of those ,members due to the magnetic reactions set up therein. Since the only force opposing the separation of the two side portions of the looped switch actuating members I! is that supplied by the contact pressure between the stationary and the moving contacts, the separation of the side portion does not result in an appreciable lessening of the contact pressure. If the handle is not held in the closed circuit position, the magnetically produced separation of the side portions oi the looped switch actuating member first moves the line of action of the over-center spring 55 to the position shown by the line 83 of Fig. 7, exactly as described for the thermostatic operation. Any subsequent or any additional separation of the side portions will then bring the line of action to the open circuit side of the pivot point of the operating member, thereby causing that member to move to the open circuit position with a snap action. This movement of the operating member 41 brings the line of action of the spring 55 to the open circuit side of the pivot point for the switch actuating member 11 and causes a sim.

position with a snap action.

Whether the operation is substantially instantaneous as a result of the magnetic reaction set up by the flow of large magnitude currents through the looped switch actuating members ll, or whether the operation is after a time'delay due to heating is immaterial insofar as the time of separation of the cooperating contacts is concerned. If the handle is free, the contacts are biased together with a definite force up-until the instant of contact separation, and if the handle is held down, the same is true although the contact pressure decreases to a zero value at the exact instant of separation. In either case, however, the movable contacts are moved to the open circuit position by the switch actuating means witha snap action.

This feature of positive quick make and quick break in combination with means for securing contact pressure up until the instant of contact separation is one of the ways in which my invention distinguishes from the structures heretofore known in the art. The novel arrangement of the offset pivot points permits the maintaining of the separable contacts in engagement under a predetermined biasing force until the instant of separation, as pointed out above, and by so proportioning the several elements of the operating mechanism that the contacts do not move to the open circuit position until the line of action of the spring has passed to the open circuit side of the contact actuating member, positive opening of the circuit is assured under any possible circuit condition.

As was previously pointed out, the operating member 41 is connected to the bifurcated operating handle 3| through a lost motion connection, the upstanding end 53 of the projection 49 being engageable by the downward projections 5| from the handle member itself. Thus, during the normal manual operation of the circuit interrupter, the operating handle itself serves merely to start the operating member 41 in motion, and by means of this lost motion connection permits that member to move without further restraint either to the open circuit position or to the closed circuit position independently of the movement of the operating handle itself. This feature is of value in preventing improper operation-of the interrupter which might result from amovement of the operating member in one direction immediately followed by a backing oil of that member in the other direction, thus causing the contacts to move into and out of engagement.

The adjusting screw 5! permits the interrupter to be easily calibrated over any reasonable range of current values and also serves as a ready means for taking up any inaccuracies in the manufacture or assembly of the parts. Since the looped bimetallic switch actuating members ll carry the entire line current,'the heating and subsequent deflection of those members is a function of the current in' the controlled circuit. Thus, the movement of the end of the switch actuating member to which the over-center spring 55 is connected is dependent upon the current flowing in that member at any particular time. The position of the end of the operating member 41 to which the spring 55 is connected determines how far the movable end of the switch actuatin members 11 must move tobring the line of ac- The magnetic opening of the breaker is dependent chiefly upon the current flowing in the switch actuating members H, the length of the opposed looped portion, and their relative spacing and stillness, the inherent resiliency of the members being used as a biasing means for opposing and controlling the opening of the circuit interrupter in response to the magnetic reaction therebetween. This feature is thus most readily changeable through the provision of different switch actuating members.

If the looped switch actuating member be considered as comprising a switch arm having affixed thereto a bimetallic electro-responsive element for engaging the switch actuating means, it becomes apparent that the device is a circuit .interrupter which is operated by a multiple-link,

over-center spring actuating mechanism having one of the links thereof of thermally responsive material. This mechanism is, of course, applicable to numerous types of multiple-link, overcenter spring, or tumbler actuated devices, be-

cause it combines all of the desirable features of a multiple link mechanism with an inherent responsiveness to predetermined conditions. In a circuit breaker, the arrangement permits the contact actuating linkage itself to serve the functions ordinarily accomplished by both the actuating linkage and the trip device; the resulting saving in manufacturing cost is very appreciable.

While I have disclosed a device wherein the thermally responsive switch actuating member is heated by the current flow therein, it is, of course, possible to secure the novel operation described by merely causing relative movement between the line of action of the over-center spring and tion of the over-center spring across .the pivot point of the operating member. As a result, the

calibration of the circuit interrupter may be readthe several pivot points. Other means for dolnz this are shown, for example, in the application of Harlan S. Geno, Serial No. 106,782, filed 0ctober 21, 1936, andassigned to the assignee of this application. It is my intention, therefore, that the claims should read on structures which may be modified in this manner.

It will thus be seen that I have disclosed a new and novel circuit interrupting device which combines a greater number of desirable features than has any device heretofore known the art.- My circuit breaker is trip free of the die in all msitions; it-is quick make and \uick break; the contacts are only moved to the open circuit position when the line of action of the operating spring has moved to the open circuit side of the support point for the switchactuating member, thus assuring contact pressure up until the instant of contact separation; it is capable of automatically opening the circuit after a predetermined time delay upon the occurrence of an overload condition in the controlled circuit; it is capable of automatically opening the circuit substantially instantaneously upon the occurrence of a short circuit condition; and the device is readily'adjustable. In addition to the above, I have disclosed a novel quick acting, multiplelink, mechanism utilizing offset pivot points for the several links and thermally responsive material for one of the links itself.

- While, in accordance with the patent statutes,

'1 have given the foregoing details of a practical embodiment of my invention, it is to be understood that many of these details are merely illustrative and that variations in their precise form will be desirable in some applications. I desire, therefore, that the language of the accompanying claims shall be accorded the broadest reasonable construction, and that my invention be limited only by what is explicitly stated in the claims andbythe prior art.

I claim as my invention:

1. In electrical apparatus, means for opening and for closing a circuit, said means being actuated to the open and to the closed position by a member having one point thereof movable to actuate said means to the open and to the closed position and being supported at a second point thereof, spring exerting a force having a line of action normally lying to one side of said second point at which said actuating member is supported, a second force exerting means responsive to a predetermined condition for automatically producing relative movement between said line of action and said second point, whereby said line of action is moved to the opposite side of said second point, the force for effecting relative movement ot said line of action and said second point being, supplied by said force exerting means responsive to a predetermined condition, and an operating member movable to apply a force to said spring means at a point spaced from the point where said second force exerting means applies its force, said means for opening and for closing the circuit remaining in the closed position until there has been suiiicient relative movement of said second point and said line of action to cause said line of action to lie on the said opposite side of said point.

2. In a circuit interrupter, means for opening and closing the circuit, and actuating means therefor, said actuating means comprising a pivoted member having at least a portion thereof of thermally responsive material, and an overcenter spring for moving said pivoted member to the open and to the closed circuitposition with a snap action, said portion of thermally responsive material being movable when heated to cause relative movement between the line of action of said spring and the pivot point of said actuating member.

3. In a circuit interrupter, means for opening and closing the circuit, and actuating means therefor, said actuating means comprising a member having at least a portion thereof of himetallic material, said member being pivoted intermediate its ends, and an overcenter spring which is operatively connected to one end of said pivoted member for moving said member to the open and to the closed circuit position with a snap action, said portion of bimetallic material being movable when heated to cause relative movement of the line of action of said spring and the pivot point of said actuating member.

4. In a circuit interrupter, means for opening and closing the circuit comprising a looped member of bimetallic material having a contact means at one end, said member being pivotally supported adjacent the closed end of said loop, and

an overcenter spring operatively connected to the other end of said looped member for moving said member to the open and to the closed circuit position with a snap action, said looped member being movable when heated to cause relative movement of the line of action of said spring and the pivot point of said looped member.

5. In a thermostatic device, a member having a portion thereof of thermally responsive bimetallic material, said member having a contact member adjacent one end thereof, a pivot point intermediate the ends thereof, and means actuated in response to movement of the other end of said member for controlling the movement of said member about said intermediate pivot point.

6. In a circuit interrupter, means for opening and closing the circuit, including a movable current responsive means. biasing means movable from a position biasing said means for' opening and closing the circuit to the closed position to a position biasing said means for opening and closing the circuit to the open position, and an operating member, said biasing means being'movable by a force applied thereto by said current responsive means to cause said biasing means to bias and thereby move said means for opening and closing the circuit to the open circuit position irrespective of the position of said operating member.

7. In a circuit interrupter, means for opening and closing the circuit including a movable contact carrying member having at least a on thereof of thermally responsive material, overcenter spring connected at one end to said contact carrying member, an operating member operatively connected to the other end of said spring for actuating said means for opening and closing the circuit, andmeans for heating said portion of thermally responsive material in response to the current in the controlled circuit, said portionof thermally responsive material being movable when heated to cause said overcenter spring to move said means for opening and closing the circuit to the open circuit position irrespective of the position of said operating memher.

8. In a circuit interrupter, means for opening and closing the circuit including a pivotally supported switch actuating member, a pivotall supported operating member which is connected to said switch actuating member by a spring, the pivot points of said switch actuating member and said operating member being so positioned that the line of action of said spring first passes, during the closing operation, across the pivot point of said switch actuating member, and then passes across the pivot point of said operating member, said pivotally supported switch actuating member including means of bimetallic material normall movable with the switch actuating member about its pivot, said means of bimetallic material when heated causing the line of action of said spring to be moved relative to the pivot point of said operating member to cause the switch actuating member to move to the open' circuit position witha snap action, and means for effecting the heating of said means of bimetallic during the closing operation, across the pivot point of the switch actuating member and then passes across the pivot point of the operating member, said overcenter spring being connected to said switch actuating member through means of bimetallic material which is movablewhen heated to relatively shift the line of action of said overcenter spring with reference to the pivot point of said operating member thereby causing said spring to move said switch actuating member to the open circuit position with a snap action, and means for effecting the heating of said bimetallic connecting means in response to the electrical conditions in the circuit controlled by said interrupter.

10. In a circuit interrupter, means movable to open and to close the circuit including a contact making member, an operating member, means of bimetallic material joined at one end to said contact making member, and a spring aflixed at one end to said means of bimetallic material and at the other end to said operating member and actuable by said operating member to move said contact making member to the open and to the closed circuit position, said means of bimetallic material being heated in response to the current flowing in said means movable to open and to close the circuit and being movable when heated so as to cause the line of action of said spring to be positioned where said spring shall move said means movable to open and to close the circuit to the open circuit position independently of the position of said operating member.

11. In combination, means movable to two extreme positions, and a multiple linkage actuating means for moving said means movable to two extreme positions from one position to the other, one of the links of said actuating means having at least a portion thereof of thermally responsive material, movable when heated to prevent the moving of said means movable to two extreme positions by said actuating means to one of said positions.

12. In a circuit interrupter, means for opening and for losing the circuit, a multiple linkage actuating means for moving said means for opening and for closing the circuit to the open and to the closed circuit position, one of the links of said actuating means having at least a portion thereof of bimetallic material, and means for causing the heating of said thermally responsive portion, said thermally responsive portion being movable when heated to shift the center line of at least one link of said linkage to a position where said actuating means is incapable of holding said means for opening and for closing the circuit in the closed circuit position.

13. In a circuit interrupter, means for opening and for closing the circuit including a pivoted switch actuating member, an operating member, an overcenter spring for operatively connecting said switch actuating member and said operating member, said overcenter spring engaging said switch actuating member through a connecting means having at least a portion thereof of thermally responsive material, and means for eflecting the heating of said thermally responsive portion of said connecting means, said thermally responsive portion of said connecting means being movable when heated to cause the line of action of said overcenter spring and the pivot point of said switch actuating member to be relatively moved so as to cause said overcenter spring to move said means for opening and closing the circuit to the open circuit position irrespective of the position of said operating member.

14. In a circuit interrupter, means for opening and closing the circuit including a switch actuating member, an operating member, an overcenter spring for operatively connecting said switch actuatins member and said operating member, said switch actuating member, said operating member and said overcenter spring forming together a multiple link mechanism for moving said means for opening and for closing the circuit to the open and to the closed circuit position with a snap action, said switch actuating member having at least a portion thereof of bimetallic material which is connected in electro-responsive relationship with the circuit controlled by said interrupter, said portion being movable when heated to cause said overcenter spring to automatically move said mechanism to the open circuit position and to prevent the closing of the circuit by said operating member.

' 15. In a circuit interrupter, means for opening and for closing the circuit, biasing means for causing opening of the circuit, a looped current carrying bimetallic member, the opposed side portions of said looped member being relatively movable when said interrupter is in the closed circuit positions in response to the magnetic reaction set up by current flow therein, said biasing means being actuable in response to predetermined movement of said opposed side portions to cause said means for opening and for closing the circuit to be moved to the open circuit position.

16. In a circuit interrupter, means for opening and for closing the circuit including a looped current carrying switch member that is supported at a point intermediate its ends, and an actuating mechanism therefor, the opposed sides of said looped member being relatively movable when said interrupter is in the closed circuit position in response to the magnetic reaction set up by current flow therein, said actuating means operatively engaging said means for opening and for closing the circuit through said looped member and being actuable in response to predetermined movement of said opposed side portions to cause said means for opening and closing the circuit to be moved to the open circuit position.

17. In a circuit interrupter, means for opening and for closing the circuit including a looped current carrying switch actuating member that is pivotally supported adjacent the closed end of said loop, and an actuatingmechanism therefor including an overcenter spring which engages one end of said looped switch actuating member, I

the line of action of said spring being relatively shiftable from one side of the pivot point of said switch actuating member to the other when said means for opening and for closing the circuit is moved from one position to the other, the opposed sides of said looped switch actuating member being relatively movable in response to the magnetic reaction set up by a predetermined current flow therein to cause a suillcient relative shift between the line of action of said spring and said pivot point to cause said mechanism to automatically move said means for opening and for closing the circuit to the open circuit .position.

18. In a circuit interrupter, means for opening and for closing the circuit, and a multiple linkage actuating means for moving said means for opening and for closing the circuit to the open and to the closed circuit position, one of the links of said actuating means having at least a portion thereof of thermally responsive material movable when heated to prevent the closing of the circuit by said actuating means, said actuating means having means associated therewith for defining the amount of movement of said portion of thermally responsive material necessary to prevent the closing of the circuit by said actuating means.

19. In a circuit interrupter, means for opening and for closing the circuit including a pivoted switch actuating member having at least a actuating means including an overcenter spring and an operating member for engaging said switch actuating member and for moving said means for opening and for closing the circuit to the open circuitand to the closed circuit position, said portion of thermally responsive material being movable when heated to cause sumcient relative movement between the line of action of said spring and the pivot point of said switch actuating member to cause said means for opening and for closing the circuit to be automatically moved to the open circuit position, and adjustable stop means associated with said actuating mechanism for defining the amount of movement of said portion of thermally responsive material necessary to cause sufllcient relative movement between the line of actionof said spring and the pivot point of said switch actuating member to effect said opening of the circuit thereby.

20. In a circuit interrupter, separable contacts. actuating means including a handle for normally moving one of said contacts both to open and to close the electrical circuit through said interrupter, means including at least one movable,

current-carrying, bimetallic portion, which is operable upon the occurrence of predetermined conditions to cause said actuating means to automatically move said contact to the open circuit position, and a conducting portion disposed adjacent said bimetallic portion so as to form therewith a pair of conducting paths through which current flows, the flux thereby produced causing said bimetallic portion to move so as to effect the automatic opening of said interrupter upon the occurrence of other predetermined conditions.

21. In a circuit interrupter, separable contact means for opening and for closing the electrical circuit through said interrupter, actuating means for said contact means including means for bias ing said contact means to move to open circuit position, a bimetallic member, at least a portion of which is movable upon the occurrence of predetermined conditions which persist for a predetermined interval of t me to cause said biasing means to move said contact means to the open circuit position, and means for producing a magnetic field adjacent said bimetallic member in order to effect the high speed opening of said interrupter by said biasing means upon the occurrence of other predetermined conditions, said fleld producing means comprising a conducting portion disposed adjacent the movable portion of said bimetallic member and means for causing electrical current to flow through said conducting portion and through said movable portion of the bimetallic member.

22. In a circuit interrupter, contact means for opening and for closing the electrical circuit therethrough, actuating means including biasing means for moving said contact means, and electro-responsive means operable upon the occurrence of at least two different sets of predetermined conditions to cause said biasing means to move said contact means to open the electrical circuit through said interrupter, said electro-responsive means including a pair of current-carrying portions. at least one of which is of bimetallic material, normally disposed adjacent each other in a substantially parallel relationship and means for electrically interconnecting said portions so that the energizing current therefor flows there-v through, said portion of bimetallic material being movable when heated by the flow therethrough of currents of predetermined magnitude for a predetermined interval of time to effect the operation of said electro-responsive means, and at least one of said portions being movable substantially instantaneously when the reaction force of the flux set up by the flow of current through said members reaches a predetermined value to eflect the operation of said electro-responsive means.

23. me, circuit interrupter, contact means for opening and for closing the electrical circuit therethrough, actuating means for said contact means, including at least one operating spring, and an electro-responsive means operable upon the occurrence of at least two different sets of predetermined conditions to cause said operating spring to move said contact means to open the electrical circuit through said interrupter, said electro-responsive means including a pair of ourrent-carrying members of bimetallic material normally disposed adjacent each other in a substantially parallel relationship, means for electricaliy connecting each of said members into current responsive relationship with the electrical circuit through said interrupter and means for electrically interconnecting said members in such manner that the normal flow of current therethrough is in opposite directions, at least one of said members of bimetallic material being movable, after a predetermined time interval, in response to the flow therethrough of predetermined low magnitude currents to effect the operation of said electro-responsive device, and at least one of said members of bimetallic material being movable substantially instantaneously to effect the operation of said electro-responsive means by the reaction force of the flux generated by the flow through said parallel members of predetermined large magnitude currents.

24. In a circuit breaker, a pair of contact members one of which is movable to open and close the circuit, a bimetallic member mounted to move bodily with said movable contact member, said bimetallic member being in the form of a loop with the distance between the sides thereof variable upon change of temperature, a manually operable member for moving said movable com tact to close the circuit, said manually operable member being connected to said movable contact only through said bimetallic member, and a spring for biasing said movable contact to open the circuit upon change in temperature of said bimetallic member.

25. In a circuit breaker, a pair of contact members one of which is movable to open and close the circuit, a b'metallic member mounted to move bodily with said movable contact member, said bimetallic member being in the form of a loop with the distance between the sides thereof variable upon change of temperature, a handle member for manually moving said bimetallic member and said movable contact in unison to normally both open and close the circuit, said handle member moving said movable contact only by the force transmitted through said bimetallic member, spring for biasing said movable contact, said spring being operative in response to movement of said bimetallic member to move said contact to open circuit position upon the occurrence of an abnormal condition and irrespective of the position in which said handle may be held.

'26. In a circuitbreaker, a handle member, a pair of contact members one of which is movable to open and close the circuit, a spring operable to move said movable contact to open-circuit position with a snap action, a bimetallic member oi U-shape having the distance between the pm ends of the U variable in response to change or temperature, said bimetallic member normally actuating one 0! said contacts upon movement 0! said handle member, and said bimetallic member being responsive to the current through the circuit breaker and causing said spring to move the movable contact to open-circuit position upon the occurrence of a predetermined electrical condition of the circuit.

27. In a circuit breaker, a pair of contact memhere one of which is movable to open and close the circuit, an operating member for normally moving said movable contact to open-circuit position and to closed-circuit position, a spring operable to move said movable contact to open-circuit position with a snap action, a bimetallic member of U-shape having the distance between the open ends of the U variable in response to change of temperature, said operating member being connected to said movable contact only through said bimetallic member, and said bimetallic member being responsive to the current through the circuit breaker and causing said spring to move the movable contact to open-circuit position upon the occurrence of a predetermined electrical condition of the circuit, irrespective of the position in' which said operating member may be held.

aseaooi and said spring causing said movement of the movable contact out of engagement with the contact mounted on the base irrespective of the po- 4 tion thereof 01' thermally responsive material, said 28. In a circuit breaker, a base member, a contact mounted thereon, a switch member mounted on said base member and movable relative thereto, a movable contact mounted on said movable switch member for engaging and diseng in said contact on the base member uponmovement of the movable switch member, said movable switch member including a strip of bimetallic material forming the sole support of said movable contact from said base as it moves relative thereto, said strip of bimetallic material being responsive to the electrical condition of the circuit through the circuit breaker, and a spring for causing movement of said movable switch member and the movable contact mounted thereon out of engagement with the contact mounted on the base member with a snap action in response to movement of the end of said strip of bimetallic material away from said movable contact.

29. In a circuit breaker, a base member, a contact mounted thereon, a switch member mounted for pivotal movement on said base member, a movable contact carried by said switch member for engaging and disengaging said contact on the base upon movement 0! said switch member about its pivot, said switch member including a strip of bimetallic material positioned between the movable contact and the pivot of the switch member and forming the sole support of said movable contact from said pivot, said strip of bimetallic material being responsive to the electrical condition of the circuit through the circuit breaker, and a spring for causing movement of said switch member and the movable contact carried thereby out of engagement with the contact on the base with a snap action in response to movement of said strip of bimetallic material.

30. In a circuit breaker, a base member, a contact mounted thereon, a switch member mounted on said base member and movable relative thereto, a movable contact mounted on said movable movable member having one of said contacts mounted thereon for movement therewith, a pivoted link, 'anda spring fastened to one end of the link for moving said movable member to the open and to the closed circuit position with a snap action, said portion of thermally responsive material being movable when heated to cause said pivoted link to change the direction of the force exerted by kid spring from biasing said movable member and the contact mounted thereon into engagement with the other contact to bias said movable member and thecontact mounted thereon to move out oi engagement with the other contact.

32. In a circuit interrupter, a pair of contacts for opening and closing the circuit, and actuating means therefor, said actuating means comprising a member 01' bimetallic material having one of said contacts mounted thereon for movement therewith, a non-resilient pivoted link, and a tension spring fastened at one end to the link for moving said bimetallic member and the contact mounted thereon to the open and to the closed circuit position with a snap action, said spring biasing said bimetallic member and the contact mounted thereon into engagement with the other contact when the interrupter is in the closed circuit position and said bimetallic member being movable when heated to cause said pivoted link to change the direction of the force exerted by said spring to bias said bimetallic member and the contact mounted thereon to move out of engagement with the other contact.

33. In a circuit interrupter, a pair of contacts for opening and closing the circuit, a base mem-- ber having one of said contacts mounted thereon, and actuating means for the other of said contacts, said actuating means including a bimetallic member having said other contact mounted thereon for movement therewith, a relatively rigid pivoted link having one end remaining relatively fixed with respect to the base and movable at the other end, and a spring fastened to the link for moving said bimetallic member and the contact mounted thereon to the open and closed circuit positions with a snap action, said spring biasing and for closing a circuit, said means being actuatedtothe open andtotheclosed positionby a member having one point thereof movable to actuate said means to the open and to the closed position and being supported at a second point thereof, means exerting a force having a line of action normally lying to one side of said second point at which said actuating member is supported, an operating member movable between an open and a closed position for causing movement of said line of action back and forth across sa d second point to open and close the circuit at will under ordinary conditions, and a second force exerting means responsive to a predetermined condition and operable independently of the position in which said operating member may be held for automatically producing relative movement between said line of action and said second point, whereby said line of action is moved to the o p site side of said second point, the force for effecting relative movement of said line 01' action and said second point being supplied by said force exerting means responsive to a predetermined condition, said means for opening and for clo in the circuit remaining in the closed position unti there has been suiiicient relative movement of said second point and said line of action to cause said line of action to lie on the said op SidP oi said point. I

35. In electrical apparatus, means for opening and for closing a circuit, said means being actuated to the open and to the closed position by a member having one point thereof movable to actuate said means to the open and to the closed position and being supported at a second point thereof, means exerting a force having a line of action normally lying to one side of said second point at which said actuating member is supported, an operating member movable between an open and a closed position for causingmovement of said line of action back and forth across said second point to open and close the circuit at will under ordinary conditions, and a second force exerting means responsive to a predetermined condition and operable independently of the pontion in which said p rating member may be held for automatically producing relative movement between said line of action and said second point, whereby said line of action is moved to the opposite side of said second point, the force for effecting relative movement of said line of action and said second point being supplied by said force exerting means responsive to a predetermined condition, said means for opening and for closing the circuit remaining in the closed position until there has been suflicient relative movement of said second point and said line of action to cause said line of action to lie on the said opposite side of said point, and said movement of said line of action in response to said predetermined condition causing said operating member to move to its open position if not held and the reclosing of said means for opening and closing the circuit then requiring only movement or the operating member to closed position.

36. In a circuit. interrupter, means for opening and closing the circuit, current responsive means movable upon the occurrence of an abnormal condition, biasing means movable from a position biasing said means for opening and closing the circuit to th closed position to a position biasing said means for opening and closing the circuit to the open position, and an operating member movable manually for normally actuating said biasing means to open and close the circult with a snap action, said biasing means having a force applied thereto by said current responsive means upon the occurrence oi an abnormal condition to cause said biasing means to bias and thereby move said means for opening and closing the circuit to the open circuit position irrespective of the position oi said operating member.

37. In a circuit interrupter, contact means pivotally mounted for opening and closing the circuit, an operating mechanism for said contact means including a current responsive means movable upon the occurrence of predetermined conditions, a pivoted operating member, a biasing spring connected at one end to move said contact means about its pivot and at the other end to said operating member, said biasing spring being movable from a position biasing said pivoted operating member and said contact means to the closed position to a position biasing said contact means to the open position, said operating member being movable to cause said biasing spring to move between said positions and normally open and close the contact means with a snap action and said biasing spring being movable by said current responsive means upon the occurrence of an abnormal condition to bias said contact means to the open circuit position, and said contact means when actuated upon movement of the current responsive means remaining stationary until the direction of the bias exerted thereon has crossed its pivot point and then moving to open circuit position irrespective of the position of said operating member.

38. In a circuit interrupter, switching means actuable about a fixed pivot to cause opening and closing of the circuit, a pivoted operating member, a biasing spring connected at one end to actuate said switching means and at the other end to said pivoted operating member, said operating member being movable about its pivot to carry the line of action of the biasing spring across the fixed pivot of the switching means to move the switching means to open and closed positions with a snap action, and current responsive means operable upon the occurrence of a predetermined condition to apply a force to said biasing spring and move its line of action across the fixed pivot of said switching means, even though said operating member may be held in closed position, and cause said biasing spring to initiate movement of said switching means to open the circuit.

39. In a circuit interrupter, a contact member mounted to move about a fixed pivot for opening and closing the circuit, a, pivoted operating member, a tension spring connected at one end 'to actuate said contact member and at the other end to said pivoted operating member, a handle member for moving said operating member about its pivot and thereby move the direction of the bias of said tension spring across the pivot of the operating member and across said flxed pivot oi the contact member to normally move it to open and closed positions with a snap action, 'and current responsive means operable upon the occurrence of a predetermined abnormal condition to apply a force to said tension spring and move the direction of its bias on said contact member across the pivot of said contact member, said contact member remaining in closed position after movement of said current responsive means until said tension spring has moved to bias it to open position and then moving to open position even though said handle member maybe held in closed position.

40. In a circuit interrupter, a contact member mounted to move about a tired pivot for opening and closing the circuit, a pivoted operating member, a tension spring connected at one end to actuate said contact member and at the other end to said pivoted operating member, a handle member for moving said operating member about its pivot and thereby move the direction of the bias of said tension spring across said iixed pivot of the contact member to normally move it to open and closed positions with a snap action, and current responsive means operable upon the occurrence of a predetermined abnormal condition to app y a force to said tension spring and move the direction of its bias on said contact member across the pivot of said contact member, said contact member remaining in closed position after movement of said current responsive means until said tension spring has moved to bla it to open position and then moving to open position even though said handle member may be held in closed position, said handle member when released aiter being held in closed position being automatically moved to open position by said tension spring and the circuit interrupter then requiring only movement 01' the handle member to closed position to return the contact member to closed position.

41. In a circuit interrupter, means for opening and closing the circuit, including current responsive means movable upon the occurrence of predetermined conditions, biasing means movable .i'rom a position biasing said means for opening and closing the circuit to the closed position to 44. In a manually and automatically operable circuit breaker, a pivoted element, a contact carried thereby, a manually oscillatable member, an operating spring biasing said element about its pivot and connected to be moved by said memher for movement past the pivot of said element, means for quickly changing the directional torque of said spring independently of the speed of movement of said member when said member has been manually operated to a certain position, said operating spring also being operable to cause automatic opening of the circuit breaker, and said contact having connected in series therewith a portion oi bimetallic material movable upon the occurrence of a predetermined condition to initiate the automatic opening of the circuit breaker by said operating spring and said automatic opening taking place irrespective of the position in which said manually oscillatable member may be held.

45. In a circuit breaker, stationary and movable contacts, a movable element having an operative connection to the movable contact, a movable member, a spring biasing said element and movable by said member through a dead center" position to actuate said element in diiierent directions, and means to quickly move the spring through its dead center position irrespective of the speed of movement of said member when said able by said current responsive means to bias and move said means for opening and closing the circuit to the open circuit position even though said operating member may be held in closed position, said operating member when released after being held in closed position being moved to open position by said biasing means and the circuit interrupter then requiring only movement of the operating member to closed position to return the circuit interrupter to closed position.

42. In a circuit interrupter, switching means movable about a pivot to cause opening and closing of the circuit, a pivoted operating member, a biasing spring connected at one end to actuate said switching means and at the other end to said pivoted operating member, said operating member being movable about its pivot to carry the line of action of said biasing spring across the pivot of said switching means to move it to Open and closed positions with a snap action, current responsive means operable upon the occurrence of a predetermined condition to move the direction of the biasing force exerted on said switching means across the pivot oi the switching means to move it to open the circuit even though said operating member is held in closed position, said operating member when released after being held in closed position being moved by said biasing spring to open position, and the circuit interrupter then being operable by movement of the operating member to closed position to move said switching means to close the circuit.

43. In a circuit breaker, a pivoted element, a contact carried thereby, a manually oscillatable member, an operating spring biasing said element about its pivot and connected to be moved by said member for movement past the pivot of said element and means for quickly changing the member has been manually operated to a certain position.

46. A circuit breaker comprising a base, a stationary contact on said base; a movable contact, a pivotal element operatively connected to said movable contact, a manually operable member, an over center spring operated by said member to move said element and means to quickly move said spring past dead center irrespective of the speed of operation oi said member when said member has been manually operated to a certain position.

47. In a circuit breaker, a movable contact, a pivoted element having operative connection therewith, a movable member, a spring biasing said element about its pivot and movable on opposite sides of the pivot point by said member,

and means for moving said spring quickly through dead center position-irrespective 'ot the speed of movement of the member when said member has been manually operated to a certain position.

48. In a circuit breaker, a pivoted element, a contact mounted thereon, a movable member, a spring biasing said element and connected to be moved by said member and movable past the pivot oi said element to eflect snap e ent f s contact, and means for moving said spring quickly through dead center position irrespective of the speed of the movement of said member when said member has been manually operated to a certain position.

49. In a circuit breaker, a movable-contact. a pivoted element having operative connection therewith, a movable member, a spring biasing said element about its pivot and movable on opposite sides of the pivot point by said member, and means for moving aid spring quickly through dead center position irrespective of the speed of movement of the member, the said element being movable on overload to eiiect automatic movement of said contact.

50. In a manually and automatically operable circuit breaker, stationary and movable contacts, a movable element having an operative connection to the movable contact, a movable member, a spring biasing said element and movable by said member through a "dead center" position to actuate said element in different directions,

. means to quickly move the spring through its "dead center" position irrespective of the speed of movement 01' said member when said member has been manually operated to a certain position, said contacts having means responsive to current connected in series therewith, and said means responsive to current being operable to cause automatic opening of the contacts upon the occurrence of a predetermined condition irrespective of the position in which said movable member maybeheld.

51. In a manually and automatically operable circuit breaker, a pivoted element, a contact mounted thereon, a movable member, a spring biasing said element and connected to be moved by said member and movable past the pivot of said element to effect snap movement of said contact, means for moving said spring quickly through dead center position irrespective of the speed of the movement of said member when said member has been manually operated to a certain position and said contact having connected in series therewith a portion of bimetallic material operable to cause automatic opening of said contact upon the occurrence of a predetermined condition,

52. A manually and automatically operable circuit breaker comprising a base, a stationary contact on said base, a movable contact, a pivotal element operatively connected to said movable contact, a manually operable member, an over center spring operated by said member to move said element and means to quickly move said spring past dead center irrespective oi the speed of operation of said member when said member has beenv manually operated to a certain position, and said over center spring being operable upon the occurrence of a predetermined electrical condition to actuate said movable contact to open the circuit.

53. In a manually and automatically operable circuit breaker, a movable contact, a pivoted element having operative connection therewith, a movable member, a spring biasing said element about its pivot and movable on opposite sides of the pivot point by said member, means for moving said spring quickly through dead center position irrespective oi the speed of movement of the member when said member has been manually operated to a certain position, said contact having associated therewith thermal means responsive to the current flow therethrough and operable to initiate automatic opening of said contact upon the occurrence of a predetermined condition.

54. In an automatic electric circuit breaker, separable contacts, means for biasing said contacts to separated position, and current responsive means for causing actuation of said contacts by said biasing means to said position, said current responsive means including a current traversed, bimetallic stri having relatively fixed and free ends when said contacts are in engaged position with its free end progressively movable in a direction at right angles to the plane of the free end of the strip, said strip being provided with means for supporting it at a point adiacent its mid portion so that said point and said relatively fixed end remain substantially stationary during the progressive movement of said free end prior to separation of the contacts.

55. In an automatic electric circuit breaker.

stationary and movable contacts, manual means for moving said movable contact to enzased and disengaged positions, a member releasable to cause automatic movement or said movable contact to disengaged position, and means for releasing said member including a current traversed, progressively movable, bimetallic member and means for supporting said bimetallic member adjacent its middle portion and maintaining one end relatively stationary while the other end moves progressively to the positkm where automatic separation oi! the contacts is caused.

56. In an automatic electric circuit breaker, separable contacts, manual operating means for said contacts, current e means for causing automatic separation of said contacts in re.- sponse to overload, said current responsive means including a current traversed, vely moving, bimetallic member formed of layers of metals or diiiferent temperature coetlicimt oi expansion and mean for supporting said bimetallic member adjacent its middle portion and maintaining one end relatively stationary while the other end moves progressively to the position where automatic separation of the contacts is caused.

57. In an automatic electric circuit breaker, stationary and movable contacts, means for biasing the movable contact to separated position and means for releasing the movable contact for movement to said position. said means includin a bimetallic member formed of layers of metals of diilerent temperature coeflicient oi! expansion integrally joined together and having relatively fixed and free ends with its free end progressively movable in response to chang in temperature and means for supporting the bimetallic member intermediate its ends.

58. In an automatic electric circuit breaker, separable contacts, means for biasing said contacts to separated position, a manually operable handle for moving the contacts between engaged and separated positions, means for releasing said contacts for movement to said position, said means including a bimetallic member formed of layers of metals of different temperature coefficient of expansion and having relatively fixed and free ends with its free end progressively movable in response to change in temperature, said member being provided with means for supporting it adjacent its middle portion.

59. In a circuit interrupter, means for opening and closing the circuit including a contact element movable about a pivot to open and closed positions, a pivoted operating member, a spring connected at one end to move said contact element about its pivot and connected at its other end to said operating member, said spring being movable by said operating member back and forth across the pivot of said contact element to thereby alternately bias said contact elementto move to open and close the circuit with a snap action, and means responsive to a predetermined condition for applying a force to said spring at a point spaced from the end thereof connected to said operating member for moving said spring across the pivot of said contact element and thereby causing said spring to bias said contact element to move to open position even through the end of the spring connected to said operating memberisheidtopreventmovementolmidendof the spring.

60. In a circuit interrupter, a contact element movable about aflxedpivottoopmandciose the circuit. an operatin member movable between an "on" and an "oi!" positim about a fixed pivot adjacent the fixed pivot of said contact element, aspringconnectedatoneuidtoactintesaid contact element and connected at its other end to said operating member, said spring being movable across both of said pivots upon movement ofsaidoperatingmemberandsaidspringchanglnsthedirectionofthebiasexertedonsaidcontactelement andonsaidoperaflngmemberaait crosses their respectivepivomandmeansresponsive to a predetermined eonditim for applyin a forcetosaidspring atapointspaeediromthe end thereof connected to said operating member for moving said spring across both of said pivots and at the same time increasing the stress thereof even though the end of the spring connected tosaidoperatingmemberisheldincn"position,saidspringafterbeipgmosedacrosssaid pivots by said means biasing said contact elementtomovetoopenthe clrmitandbiaaingsaid operating member to move to "oi!" position, and said operating member at some flme after operation of said means responsive to a predetermined condition being operable by a single movement from off to "on" position to reelose the circuit.

61. In a circuit interrupter, means for opening and closing the circuit including a contact element movable between two positions, an operating member movable betwem two positions, a spring connected at one end to move said contact element and connected at its-other end to said operating member, said spring biasing said operating member to whichever of its positions it has been moved and in each case biasing aid contact element to its position to the position of said operating member,-and means responsive to a predetermined condition for applying a force to laterally move said spring at a point spaced from the end thereof connected to said operating member and said lateral motion of said spring causing it to change the direction of its bias applied to said contact element when it has been moved to a predetermined point and then acting to move said contact element to the other position even though the end of the spring connected to said operating member is held in its original position, and said spring when moved laterally by said current responsive means to a predetermined point also changing the direction 01 its bias applied to said operating member and tending to'move it away from the position which it formerly occupied.

62. In electrical apparatus, means for opening and for closing a circuit, said means being actuated to the open and to the closed position by a member having one point thereof movable to actuate said means to the open and to the closed position and being supported at a second point thereof, manually movable means exerting a force having a line of action normally lying to one side of said second point at which said actuatin member is supported, and a second force exertin means responsive to a predetermined condition for automatically producing relative movement between said line of action and said second point, whereby said line of action is moved to the opposite side of said secondpoint, the force for effecting relative movement of said line of action and said second point being supplied by said force exerting means responsive to a predetermined condition at a point spaced from the point at which said first means exerting a force is manual- I? movable, said means for opening and for closing the circuit remaining in the closed position until there has been suflicient relative movement ofsaidsecondpointandsaidlineofactionto cause said line of action to lie on the said 09- posite side of said point.

63. In a circuit interrupter, means for opening and clonng the circuit, a movable current responsive means, biasing means movable from a position biasing said means for opening and the circuit to the closed position to a position biasing said means for opening and closing the circuit to the open position, and an operating member for normally moving said biasing means by applyi g a force at one point thereof, said biasing means being movable by a force applied thereto at a second point by said current responsive means to cause said biasing means to bias and thereby move said means for opening and closing the circuit to the open circuit position irrespective of the position of said operating member.

64. In electrical apparatus, means for opening and for closing a circuit, said means being actuated to the open and to the closed position by a member having one point thereof movable to actuate said means to the open and to the closed position and being supported at a second point thereof, means exerting a force having a line of action normally lying to one side of said second point at which said actuating member is supan operating member directly engaging said means exerting a force and movable between an open and a closed position for causing movement of said line of action back and forth across said second point to open and close the circuit at will under ordinary conditions, and a second force exerting means responsive to a predetermined condition and operable independently of the position in which said operating member may be held for automatically producing relative movement between said line of action and said second point, whereby said line of action is moved to the opposite side of said second point, the force for effecting relative movement of said line of action and said second point being supplied by said force exerting means responsive to a predetermined condition, said means for-opening and for closing the circuit remaining in the closed position until there has been suflicient relative movement of said second point and said line of action to cause said line of action to lie on the said opposite side of said point.

65. In electrical apparatus, means for opening and for closin a circuit, said means being actuated to the open and to the closed position by a member having one point thereof movable to actuate said means to the open and to the closed position and being supported at a second point thereof, means exerting a force having a line of action normally lying to one side of said second point at which said actuating member is supported, an operating member movable between an open and a closed position .for causing movement of said line of action back and forth across said second point to open and close the circuit at will under ordinary conditions, and a second force exerting means operable only in response to a predetermined condition and independently of the position in which said operating member may be held for beginning to exerta biasing force tending to produce relative movement between said line of action and said second point, whereby said line 01 action is moved to the opposite side oi said second point, the iorce for efiecting relative movement of said line or action and said second point being supplied by said force exerting means responsive to a predetermined condition. said means for opening and for closing the circuit remaining in the closed position until then requiring no movement or the operating member other than a movement tion.

66. In a circuit interrupter, means for opening and closing the circuit, a movable current responsive means, biasing means movable from a position biasing said means for opening and closing the circuit to the closed position to a position biasing said means for opening and closing the circuit to the open position, and an operating member directly engaging said biasing means at one point and movable manually for normally actuating said biasing means to open and close the circuit with a snap action, said biasing means having a force applied thereto by direct engagement of said current responsive means at a second point upon the occurrence of an abnormal condition to cause said biasing means to bias and thereby move said means for opening and closing the circuit to the open circuit position irrespective of the position of said operating member.

67. In a circuit interrupter, contact means pivotally mounted for opening and closing the circuit, an operating mechanism for said contact means including a movable current responsive means, a pivoted operating member, a biasing spring connected at one end to move said contact means about its pivot and at the other end to directly engage said operating member, said biasing spring being movable from a position biasing said contact means to the closed position to a position biasing said contact means to the open position, said operating member being movable to cause said biasing spring to move between said positions and normally open and close the contact means with a snap action and said biasing spring being movable by said current responsive means upon the occurrence of an abnormal condition to bias said contact means to the open circuit position, and said contact means when actuated upon movement of the current responsive means remaining stationary until the direction or th bias exerted thereon has crossed its pivot point and then moving to open circuit position irrespective of the position of said operating member.

68. In a circuit interrupter, switching means actuable about a fixed pivot to cause opening and closing of the circuit, a pivoted operating memher, a biasing spring connected at one end to actuate said switching means and at the other end in engagement with one point on said pivoted operating member, said operating member being movable about its pivot to carry the line or action at the biasing spring across the fixed ivot oi the switching means to move the switching mean t open and closed positions with a snap action, and current responsive means operable upon the occurrence of a predetermined condition to act on said biasing spring at a secto closed posi- 1 3 end point and move the line or action thereof across the fixed pivot of said switching means, even though said operating member may be held in closed position, and cause said biasing spring to initiate movement of said switcbingmeans to open the circuit. I

69. In a circuit interrupter, a contact member mounted to move about a fixed pivot for opening and closing the circuit, a pivoted operating member, a tension spring connecte at one end to actuate said contact member and at the other end to said pivoted operating member, a handle member for moving said operating member about its pivot and thereby move the direction oi the bias oi said tension spring across said fixed pivot of the contact member to normally move it to open and closed positions with a snap action, and current responsive means operable upon the occurrence of a, predetermined abnormal condition to apply a iorce spring at a point spaced from spring connected to the pivoted her and move the direction of to said tension the end 0! the operating memits bias on said Contact member across the pivotoi said contact member, said contact member remaining in closed position after movement of. said current responsive means until said tension spring has moved across the pivot of said contact member to bias it to open position and then moving to open position even though said handle member may be held in closed position.

70. In a circuit interrupter, a contact member mounted to move about a fixed pivot for opening and closing the circuit, a pivoted operating memher. a tension spring connected at one end to actuate said contact member and at the other end to said pivoted operating member, a handle member for moving said operating member about its pivot and thereby move the direction of the bias of said tension spring acrosssaid fixed pivot oi the contact member to normally move it to open and closed positions with a snap action, and current responsive means operable upon the occurrence of,a predetermined abnormal condition to apply a force to said tension spring and move the direction of its bias on said contact member across the pivot of saidcontact member, said contact member remainin in closed position after movement or said current responsive means until said tension spring has moved across the fixed pivot oi the contact member to bia it to open position and then moving to open position even though said handle member may be held in closed position, said handle member when released after being held in closed position being automatically moved to open position by said tension spring and the circuit interrupter then requiring no manual movement or the handle member other than a movement to closed position to return the contact member to closed position.

71. In a circuit about a pivot for opening and closing the circuit,

means movable from a means for opening and closing the circuit to the closed position to a position biasing sai means for opening and closing the circuit to the open position, and an operating member, said biasing means being movable by said current responsive position biasing said said means for opening and closing the circuit to the closed position until said biasing means has been moved across said pivot of the means for opening and closing the circuit and then biasing said means for pening and closing the circuit to the open position, said operating member when released after being held in closed position being moved to open position by said biasing means and the circuit interrupter then requiring movement of the operating member only from open position to closed position to return the circuit interrupter to closed position.

72-. In a circuit interrupter, switching means movable about a tilted pivot to cause opening and closing oi the circuit, a pivoted operating member, a biasing spring connected at one end to actuate said switching means and at the other end to said pivoted operating member, said operating member being movable about its pivot to carry the line of action of said biasing spring across the fixed pivot of said switching means, said biasing spring changing the direction of the bias exerted on said switching means immediately upon each crossing of said fixed pivot to move said switching means to open and closed positions with a snap action, current responsive means operable upon the occurrence of a predetermined condition to move the direction of the biasing force exerted on said switching means across the fixed pivot oi the switching means to move it to open the circuit even though said operating member is held in closed position, said operating member when released after being held in closed position being moved by said biasing spring to open position, and the circuit interrupter then being operable by movement of the operating member to closed position to move said switching means to close the circuit.

73. In a circuit interrupter, means for opening and closing the circuit, a movable current responsive means, biasing means movable from a podtion biasing said means for opening and closing the circuit to the closed position to a position biasing said means for opening and closing the circuit to the open position, and an operating member for normally moving said biasing means to open and close the circuit, said current responsive means including a force exerting means offering no opposition to normal movement 01' said biasing means by said operating member, said biasing means being movable by said force exerting means of said current responsive means to bias and move said means for opening and closing the circuit to the open circuit position even though said operating member may be held in closed position, said operating member when released after being held in closed position being moved to open position by said biasing means and the circuit interrupter then requiring movement of the operating member only from open position to closed position to return the circuit interrupter to closed position.

'74. In electrical apparatus, a contact for opening and ior closing a circuit. a pivot point providing support for said contact, a stressed member having its line of action normally lying to one side of said pivot point, a bimetallic actuatin element responsive to a predetermined condition ior automatically producing relative movement between said line of action and said pivot point and the force for effecting said relative movement of said line of action and said second point being supplied by said bimetallic actuating element and the amount of said relative movement caused by said bimetallic actuating element being cause movement or dependent upon the amount of movement of said bimetallic actuating element, a second actuating element movable independently of said bimetallic actuating element for also producing relative movement between said line of action and said pivot point for causing movement 0! said contact, and said contact remaining in its position until there has been a predetermined relative movement between said pivot point and said line of action.

75. In electrical apparatus, a contact movable between two positions for opening and closing a circuit. a pivot point with respect to which said contact is movable, a stressed member acting to hold said contact in one of said positions when its line of action lies some distance at one side oi said pivot point and acting to hold said contact in the other position when its line oi action lies some distance at the other side of said pivot point, a current responsive bimetallic actuating element movable in response to predetermined conditions and supplying a force electing relative movement between said pivot point and said line 01' action in an amount varying during the first part of its movement with the amount 0! movement or said current responsive bimetallic element, 8. second actuating element movable independently of said bimetallic actuating element for also producing relative movement between said pivot point and said hne of action for causing movement 0! said contact, said contact when in either one oi said positions remaining there until there has been relative movement between said pivot point and said line of action to a predetermined relatlve position and then moving to its other position with a snap action, and said current responsive actuating element being movable to cause the relative movement between said pivot point and said line of action required to said contact from one position to the other even though the other actuating element has not moved the amount required to cause said movement of the contact.

76. In electrical apparatus, a contact movable between two positions for opening and closing a circuit, a pivot point providing support for said contact, a stressed member having its line of action movable relative to said pivot point for causing movement of said contact between its two positions, a bimetallic actuating element movable during the operation of the apparatus in response to predetermined conditions and supplying a force effecting relative movement between said line or action and said pivot point varying with the movement or said bimetallic actuating element, a second actuating element movable independently of said bimetallic actuating element during the operation of the apparatus for producing relative movement between said line of action and said pivot point and causing movement oi said contact, and each of said actuating elements requiring less movement than would otherwise be required to bring said line of action and said pivot point into the position relative to each other where movement or said contact is caused it the other actuating element has moved to bring said line of action and said pivot point toward said position relative to each other.

'17. In electrical apparatus, a contact movable between two positions for opening and closing a circuit, a pivot point with respect to which said contact is movable, a stressed member acting to hold said contact in one of said positions when its line of action lies some distance at one side oi said pivot point and acting to hold said contact in the other position when its line 01' action lies some distance at the other side or said pivot point, a bimetallic actuating element movable in response to predetermined conditions and supp y n a force eiiecting relative movement between said pivot point and said line of action in an amount varying during the first part 01' its movement with the amount or movement of said current responsive bimetallic element, a second actuating element movable independently of said bimetallic actuating element for also producing relative movement between said pivot point and said line or action for causing movement of said contact. said current responsive actuating element being movable to cause the relative movement between said pivot point and said line of action required to cause movement of said contact from one position to the other even though the other actuating element has not moved the amount required to cause said movement of the contact, said contact when caused to move to open position by movement of said bimetallic actuating element remaining in open position after the return of said bimetallic actuating element to its original position, and a manually operable member movable to cause return movement of said contact to closed position after movement to open position occasioned by movement of said bimetallic actuating element. I

78. In electrical apparatus, a contact movable between two positions for opening and closing a circuit, a pivot point with respect to which said contact is movable, a stressed member acting to hold said contact in one of said positions when its line of action lies some distance at one side of said pivot point and acting to hold said contact in the other position when its line of action lies some distance at the other side of said pivot point, a bimetallic actuating element movable in response to predetermined conditions and supplying a force eifecting relative movement between said pivot point and said line of action in an amount varying during the first part of its movement with the amount of movement of said current responsive bimetallic element, a second actuating element movable independently of said bimetallic actuating element for also producing relative movement between said pivot point and said line of action for causing movement of said contact, said current responsive actuating element being movable to cause the relative movement between said pivot point and said line of action required to cause movement of said contact from one position to the other even though the other actuating element has not moved the amount required to cause said movement of the contact, said contact when caused to move to open position by movement of said bimetallic actuating element remaining in open position after the return of said bimetallic actuating element to its original position, and a manually operable member movable to cause return movement or said contact to closed position after movement to open position occasioned by movement of said bimetallic actuating element, and said manually operable member being incapable of holding said contact in closed position upon movement of said bimetallic actuating element to cause opening of said contact.

79. In a circuit interrupter, means for opening and closing the circuit including a contact, a movable current responsive means, biasing means movable from a position biasing said contact to the closed position to a position biasing said contact to the open position, and an operating member movable independently oi said current responsive means and movable in one direction to cause closing movement oi said contact anddn the other direction to cause opening movement of said contact, said biasing means being connected to said current responsive means so as to be movable by the force applied thereto by said current responsive means, to cause said biasing means to bias and thereby move said contact to the open circuit position even though said operating member may be in a position which would otherwise cause closing or said contact.

Bil. In a circuit interrupter, means for opening, and" closing the circuit including a contact, a movable current responsive means, biasing means movable from a position biasing said contact to the closed position to a position biasing said contact to the open position, and an operating member movable independently of said current responsive means and movable in one direction to cause closing movement of said contact by said biasing means and movable in the other direction to cause opening movement of said contact by said biasing means even though said current responsive means may be in a condition which would otherwise cause closing of said contact, said biasing means being connected to said current responsive means so as to be movable by the force applied thereto by said current responsive means and said biasing means being initially moved by said current responsive means an amount which varies with the amount of movement of said current responsive means to cause said biasing means to bias and thereby move said contact to the open circuit position even though said operating member may be in a position which would otherwise cause closing of said contact.

81. In a circuit interrupter, means for opening and closing the circuit including a contact, a movable bimetallic element, biasing means movable from a position biasing said contact to the closed position to a position biasing said contact to the open position, said biasing means being movable laterally at one point to have its position changed upon each movement of said bimetallic element, a movable operating member connected to said biasing means at another point for applying a force to said biasing means tending to cause lateral movement thereof and the position to which said contact is biased at any time being determined by the net effect on said biasing means of the positions to which both said bimetallic element and said operating member have moved.

82. In a circuit interrupter, means for opening and closing the circuit including a contact, a movable bimetallic element, biasing means movable from a position biasing said contact to the closed position to a position biasing said contact to the open position, said biasing means being movable laterally at one point to have its position changed upon each movement or said bimetallic element, a movable operating member connected to said biasing means at another point for applying a force to said biasing means tending to cause lateral movement thereof and the position to which said contact is biased at any time being determined by the net effect on said biasing means of the positions to which both said bimetallic element and said operating member have moved. and said ,bimetallic element being movable to move said biasing means to cause said contact to be moved to open position even though said operating member may remain in a position which would otherwise have caused said contact to be in closed position.

83. In a circuit interrupter, means for opening and closing the circuit including a contact, means movable responsive to a predetermined condition, biasing means movable from a position biasing said contact to the closed position to a position biasing said contact to the open position, and an operating member movable in one direction to cause closing movement of said contact by said biasing means and movable in the other direction to cause opening movement of said contact by said biasing means, said biasing means being movable by iorce applied thereto by said means movable responsive to a predetermined condition to cause said biasing means to bias and thereby move said contact to the open circuit position, said contact when caused to move to open position by movement oi said means responsive to a predetermined condition remaining in open position after the return of said means responsive to a predetermined condition to its original position, and a manually operable member movable to cause return movement of said contact to closed position.

84. In a circuit interrupter, means for opening and closing the circuit including a contact, means movable responsive to a predetermined condition, biasing means movable from a position biasing said contact to the closed position to a position biasing said contact to the open position,

and an operating member movable in one direction to cause closing movement of said contact by said biasing means and movable in the other direction to cause opening movement of said contact by said biasing means, said biasing means being movable by force applied thereto by said means movable responsive to a predetermined condition to cause said biasing means to bias and thereby move said contact to the open circuit position, said contact when caused to move to open position by movement of said means responsive to a predetermined condition remaining in open position after thereturn of said means responsive to a predetermined condition to its original position, and a manually operable member movable to cause return movement of said contact to closed position, and said manually operable member being incapable of holding said contact erativelymaintainingsaidactuatingmemberand saidoperatingmunbermtbeiresmmepoaiflons oimovementtheplvotpointsolssidacwating memberand said operating member being oflset insuchmanmthatdm'ingeachcircuitopening operation said actuating member is biased toward the closed circuit position until after the thattheinterruptershallbeopenedwithamp action and chem-responsive means formed intcsral with said switch actuating member for causingsaidactuatingmembertomcvesaid -meansioropeningand1orclosingthecircuit fromtbeclosedtotheopencircmtpositionupon the occurrence of predetermined conditions.

86. In combination, in a circuit interrupter, meansmovabletoopenandtoclosethecircmt including a pivoted switch actuating member, a pivoted operating member, a spring means for connecting said switch acmaflng member and said operating member, said spring means "normally maintaining said switch actuating member and said operating member in their extreme position or movement, the pivot points of said actuating member and said operating member being oilset in suchmannerthatsaidspringmeansbiasessaid actuatingmembertowardtheclosedcirmitposition during each circuit opening operation until aiterthedirectionotthebiasactinguponsaid operating member changes from toward the closed circuit position to the open circuit position, means of bimetallic material which is bodily movable withsaddswitchactuatingmemberand whicnis movable when heated to cause said spring means tomcvesaidswitchacnmflngmembertotbeopen circuit positim and to prevent the moving of said switch actuating member tothe closed circuit position by said operating member, and means for r eflecting the heating of said bimetallic means.

OLIVER 8. JENNINGS. 

